You're looking at Less Wrong's discussion board. This includes all posts, including those that haven't been promoted to the front page yet. For more information, see About Less Wrong.

leplen comments on For FAI: Is "Molecular Nanotechnology" putting our best foot forward? - Less Wrong Discussion

48 Post author: leplen 22 June 2013 04:44AM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (117)

You are viewing a single comment's thread. Show more comments above.

Comment author: leplen 26 June 2013 01:05:34PM *  1 point [-]

I'd like to address just the claim here that you could provide instructions to a nanosystem with a speaker. If we assume that the frequency range of the speaker lines up with human hearing, and that our nanosystem is in water, then the smallest possible wavelength we can get from our speaker is on the order of 7cm.

lamda=v / f= 1500 m/s / 20 kHz

How can you provide instructions to a nanosystem with a signal whose linear dimension is on the order of cm? How can you precisely control something when your manipulator is orders or magnitude larger than the thing you're manipulating?

Comment author: Caspian 26 June 2013 02:58:31PM 3 points [-]

You can get microphones much smaller than 7 cm, and they can detect frequencies way lower than 20 kHz. There's no rule saying you need a large detector to pick up a signal with a large wavelength.

Comment author: asr 26 June 2013 04:06:24PM 2 points [-]

I believe the original comment isn't about the receiver, but about the emitter -- that if you use audible-range sound or even ultrasound, the spatial resolution of the signal will be impossibly large compared to a nanobot. Each nanobot will be able to get the signal, but you won't be able to only communicate with nanobots in a specific part of the body.

This might not be a fatal objection, since you could imagine some sort of protocol with unique addresses or whatnot, but it's an objection.

Comment author: Eliezer_Yudkowsky 26 June 2013 04:47:23PM 2 points [-]

This isn't about bots, it's about a little tiny factory building your second-stage materials.

Comment author: NancyLebovitz 26 June 2013 01:19:57PM 1 point [-]

You can get the effect of a huge telescope lens with an array of smaller telescopes. Could you get the same effect for sound?

Comment author: leplen 27 June 2013 12:49:20AM 2 points [-]

Sure, if you can have all your pieces coordinate and stay coordinated with other. If you do that, you still have a communication problem, just a different one.